JP6439884B1 - Soft magnetic alloys and magnetic parts - Google Patents

Abstract

A soft magnetic alloy having a low coercive force and a high saturation magnetic flux density is provided. A soft magnetic alloy including a nanocrystalline part and an amorphous part. The nanocrystal part is composed of αFe (—Si) as a main component and B, P, C, Ti, Zr, Hf, Nb, Ta, Mo, V, W, Cr, Al, Mn, Zn, and Cu as subcomponents. Contains one or more selected elements. [Selection figure] None

Description

  The present invention relates to a method for producing a soft magnetic dust core and a soft magnetic dust core.

  In recent years, low power consumption and high efficiency have been demanded in electronic / information / communication equipment and the like. Furthermore, the above demands are becoming stronger toward a low-carbon society. For this reason, reduction of energy loss and improvement of power supply efficiency are also required for power supply circuits of electronic, information, and communication devices. And the magnetic core of the porcelain element used for the power supply circuit is required to improve the permeability and reduce the core loss (magnetic core loss). If the core loss is reduced, the loss of power energy is reduced, and high efficiency and energy saving can be achieved.

  Patent Document 1 describes an invention of a dust core using a nanocrystalline soft magnetic alloy powder in which an αFe (-Si) crystal phase is partially precipitated. However, a magnetic core with a higher saturation magnetic flux density and a smaller core loss is now required.

Japanese Patent Laying-Open No. 2015-167183

  As a method for reducing the core loss of the magnetic core, it is conceivable to reduce the coercive force of the magnetic body constituting the magnetic core.

  An object of the present invention is to provide a soft magnetic alloy having a low coercive force and a high saturation magnetic flux density.

In order to achieve the above object, the soft magnetic alloy according to the present invention comprises:
A soft magnetic alloy comprising a nanocrystalline part and an amorphous part,
The nanocrystal part contains αFe (-Si) as a main component, and B, P, C, Ti, Zr, Hf, Nb, Ta, Mo, V, W, Cr, Al, Mn, Zn, Cu as subcomponents. It contains one or more elements selected from:

  Since the soft magnetic alloy according to the present invention has the above-described characteristics, the coercive force is reduced and the saturation magnetic flux density is increased.

  The soft magnetic alloy according to the present invention may have a crystallinity of 15% to 70%.

  The soft magnetic alloy according to the present invention may be 0.5 ≦ α ≦ 20, where α (at%) is a total content of subcomponents in the nanocrystal part.

  In the soft magnetic alloy according to the present invention, 10 ≦ β ≦ 60 may be set, where β (at%) is the total content of subcomponents of the nanocrystal part contained in the amorphous part.

  In the soft magnetic alloy according to the present invention, the total content of subcomponents in the nanocrystal part is α (at%), and the total content of subcomponents of the nanocrystal part contained in the amorphous part is β (at %) May be 0.05 <(α / β) <0.20.

The soft magnetic alloy according to the present invention is represented by _a composition formula Fe _a Cu _b M1 _c Si _d M2 _e ,
M1 is at least one selected from Ti, Zr, Hf, Nb, Ta, Mo, V, W, Cr, Al, Mn, Zn,
M2 is at least one selected from B, P, and C,
a + b + c + d + e = 100
0.0 ≦ b ≦ 3.0
0.0 ≦ c ≦ 15.0
0.0 ≦ d ≦ 17.5
0.0 ≦ e ≦ 20.0
It may be.

  The soft magnetic alloy according to the present invention may have a ribbon shape.

  The soft magnetic alloy according to the present invention may be in powder form.

  The magnetic component according to the present invention is made of any of the soft magnetic alloys described above.

FIG. 1 shows the result of observation of the Fe distribution in the soft magnetic alloy of the present invention by 3DAP. FIG. 2 is a schematic diagram showing the result of observing the soft magnetic alloy of the present invention with 3DAP and binarizing with the Fe content. FIG. 3 is a schematic diagram of the single roll method.

  Hereinafter, embodiments of the present invention will be described.

  The soft magnetic alloy according to the present embodiment includes αFe (—Si) as a main component. The phrase “containing αFe (—Si) as a main component” specifically means that the content of αFe (—Si) in the entire soft magnetic alloy is 80 at% or more in total. Furthermore, as a subcomponent, one or more elements selected from B, P, C, Ti, Zr, Hf, Nb, Ta, Mo, V, W, Cr, Al, Mn, Zn, and Cu are included.

  Hereinafter, the microstructure of the soft magnetic alloy according to the present embodiment will be described with reference to the drawings.

  When the Fe distribution of the soft magnetic alloy according to the present embodiment is observed at a thickness of 5 nm using a three-dimensional atom probe (hereinafter sometimes referred to as 3DAP), a portion having a high Fe content as shown in FIG. It can be observed that there are few parts. 1 shows Examples and Sample Nos. Described later. 54 is a result of observation using 3DAP.

  Here, FIG. 2 is a schematic diagram of the result of binarization of a portion having a large Fe content and a portion having a small Fe content at a measurement location different from FIG. A portion having a high Fe content is referred to as a nanocrystal portion 11, and a portion having a low Fe content is referred to as an amorphous portion 13. More specifically, with respect to the average composition of the entire soft magnetic alloy, the portion where the Fe content is larger than the average composition is the nanocrystal portion 11, the portion where the Fe content is less than the average composition and Fe is present is amorphous. This is part 13. It is considered that at least a part of Fe and Si in the nanocrystal part 11 exists in the form of αFe (-Si) nanocrystals. In the present embodiment, the nanocrystal refers to a crystal having a particle size of approximately 5 nm to 50 nm.

  The soft magnetic alloy according to the present embodiment includes B, P, C, Ti, Zr, Hf, Nb, Ta, Mo, V, W, Cr, Al, as subcomponents other than Fe and Si in the nanocrystal part 11. 1 type or more selected from Mn, Zn, Cu is included. By including the subcomponent in the nanocrystal part 11, the oxidation resistance is improved. Furthermore, the coercive force decreases while maintaining the saturation magnetic flux density. That is, soft magnetic characteristics are improved. Particularly suitable soft magnetic characteristics can be obtained in a high frequency region.

  The composition of the entire soft magnetic alloy can be confirmed by ICP measurement and fluorescent X-ray measurement. The composition of the nanocrystal part and the composition of the amorphous part can be measured by 3DAP. Here, although Cu is added to the soft magnetic alloy, the amount of Cu detected from the nanocrystal part and the amorphous part may be small or may not be detected. This is because Cu crystallites exist independently regardless of the nanocrystal part and the amorphous part. In FIG. 2, Cu crystallites are omitted.

The total content of subcomponents in the nanocrystal part 11 of the soft magnetic alloy according to the present embodiment is preferably α ≦ at ≦, preferably 0.5 ≦ α ≦ 20 and 1 ≦ α ≦ 10. More preferred. Moreover, it is preferable that 10 ≦ β ≦ 60, and more preferably 20 ≦ β ≦ 50, where β (at%) is the total content of the subcomponents of the nanocrystal part 11 included in the amorphous part 13. preferable. Further, 0.00 <(α / β) < is preferably 0.80, 0.01 ≦ (α / β ) ≦ 0.75 is a more preferred arbitrariness.

  By controlling the total content α of the subcomponents in the nanocrystal part 11 to 0.5 ≦ α ≦ 20, the coercive force can be reduced and the soft magnetic characteristics can be improved. Further, by controlling the total content ratio β of the subcomponents of the nanocrystal part 11 included in the amorphous part 13 to 10 ≦ β ≦ 60, it is possible to prevent the saturation magnetic flux density from being lowered. That is, the soft magnetic characteristics are further improved. Further, when 0.00 <(α / β) <0.80, an effect of oxidation resistance is added, so that soft magnetic characteristics can be improved and an oxidation resistance alloy can be obtained.

  The degree of crystallinity of the soft magnetic alloy according to this embodiment is preferably 15% or more and 70% or less. The crystallinity of the soft magnetic alloy can be measured by powder X-ray diffraction. Specifically, an X-ray diffraction pattern is obtained by an X-ray diffractometer (XRD) after powdering a soft magnetic alloy. Then, the asymmetry of diffraction caused by the background and the apparatus is corrected. Thereafter, the diffraction pattern of the αFe (-Si) crystal and the diffraction pattern peculiar to amorphous are separated, and the respective diffraction intensities are obtained. Then, it is obtained by calculating the ratio of the diffraction intensity of the αFe (-Si) crystal to the total diffraction intensity.

  In the soft magnetic alloy according to the present embodiment, the average grain size of the nanocrystal is not particularly limited, but is preferably 5 nm or more and 50 nm or less. The average particle diameter of the nanocrystal can be measured by powder X-ray diffraction using XRD.

The composition of the soft magnetic alloy according to the present embodiment is arbitrary except that αFe (—Si) is included as a main component and the above elements are included as subcomponents. Preferably, a soft magnetic alloy represented by _a composition formula Fe _a Cu _b M1 _c Si _d M2 _e , wherein M1 is Ti, Zr, Hf, Nb, Ta, Mo, V, W, Cr, Al, Mn, One or more selected from Zn, M2 is one or more selected from B, P, and C;
a + b + c + d + e = 100
0.0 ≦ b ≦ 3.0
0.0 ≦ c ≦ 15.0
0.0 ≦ d ≦ 17.5
0.0 ≦ e ≦ 20.0
It is.

  In the following description, regarding the content of each element of the soft magnetic alloy, unless there is a description of the parameter, the entire soft magnetic alloy is 100 atomic%.

  The Cu content (b) is preferably 3.0 atomic% or less (including 0), and more preferably 1.0 atomic% or less (including 0). That is, it is not necessary to contain Cu. Further, the smaller the Cu content, the easier it is to produce a ribbon made of a soft magnetic alloy by the single roll method described later. On the other hand, the greater the Cu content, the smaller the average particle diameter of the nanocrystals, and the greater the effect of reducing the coercive force. From the viewpoint of reducing the coercive force, the Cu content is preferably 0.1 atomic% or more.

  M1 is at least one selected from Ti, Zr, Hf, Nb, Ta, Mo, V, W, Cr, Al, Mn, and Zn. Preferably, at least one selected from Nb, Zr, and Hf is included.

  The content (c) of M1 is preferably 15.0 atomic percent or less (including 0), and more preferably 8 atomic percent or less (including 0). That is, it is not necessary to contain M1. By adding M1 within the above range (the amorphous part can be stabilized and the nanocrystal part can be formed.

  The Si content (d) is preferably 17.5 atomic% or less (including 0), more preferably 15.5 atomic% or less (including 0). That is, Si does not have to be contained. By making the Si content within the above range, the composition of the nanocrystal part can be controlled.

  M2 is at least one selected from B, P, and C. Preferably, 2 or more types are included.

  The content (e) of M2 is preferably 20.0 atomic percent or less (including 0), and more preferably 8.0 to 15.0 atomic percent. That is, it is not necessary to contain M2. By adding M2 within the above range, the composition of the amorphous part can be controlled.

Incidentally, Fe is preferably the remainder of the soft magnetic alloy represented by a composition formula _{Fe a Cu b M1 c Si d} M2 e. That is, a + b + c + d + e = 100. Further, as described above, the soft magnetic alloy of the present embodiment includes a nanocrystal part and an amorphous part. Here, two or more selected from M1, M2 and Si are necessary for forming the amorphous part. Therefore, at least two of c, d and e are not zero.

  Hereinafter, the manufacturing method of the soft magnetic alloy which concerns on this embodiment is demonstrated.

  Although the manufacturing method of the soft magnetic alloy which concerns on this embodiment is arbitrary, the method of manufacturing the ribbon of a soft magnetic alloy by a single roll method is mentioned, for example.

  In the single roll method, first, various raw materials such as pure metals of each metal element contained in the finally obtained soft magnetic alloy are prepared and weighed so as to have the same composition as the finally obtained soft magnetic alloy. And the pure metal of each metal element is melt | dissolved and mixed, and a mother alloy is produced. The pure metal can be dissolved by any method. For example, there is a method in which the pure metal is melted by high-frequency heating after evacuation in a chamber. The master alloy and the finally obtained soft magnetic alloy usually have the same composition.

  Next, the produced mother alloy is heated and melted to obtain a molten metal (bath water). Although there is no restriction | limiting in particular in the temperature of a molten metal, For example, it can be 1200-1500 degreeC.

  A schematic diagram of an apparatus used in the single roll method is shown in FIG. In the single roll method according to the present embodiment, the ribbon 34 is formed in the rotation direction of the roll 33 by injecting and supplying the molten metal 32 from the nozzle 31 to the roll 33 rotating in the direction of the arrow inside the chamber 35. Manufactured. In the present embodiment, the material of the roll 33 is not particularly limited. For example, a roll made of Cu is used.

  In the single roll method, the thickness of the ribbon obtained mainly by adjusting the rotation speed of the roll 33 can be adjusted. For example, the distance between the nozzle 31 and the roll 33, the temperature of the molten metal, etc. are adjusted. By doing so, the thickness of the obtained ribbon can be adjusted. Although there is no restriction | limiting in particular in the thickness of a ribbon, For example, it can be set as 15-30 micrometers.

  At the time before the heat treatment described later, the ribbon is preferably in a state where only amorphous or microcrystals having a small particle size are present. The soft magnetic alloy which concerns on this embodiment is obtained by performing the heat processing mentioned later with respect to such a thin strip.

There is no particular limitation on the method for confirming whether or not crystals having a large grain size are present in the soft magnetic alloy ribbon before the heat treatment. For example, the presence or absence of crystals having a particle size of about 0.01 to 10 μm can be confirmed by ordinary X-ray diffraction measurement. Further, when crystals exist in the amorphous material but the volume ratio of the crystals is small, it is determined that there are no crystals in the normal X-ray diffraction measurement. The presence or absence of crystals in this case is confirmed by obtaining a limited-field diffraction image, nanobeam diffraction image, bright-field image, or high-resolution image using a transmission electron microscope, for example, on a sample sliced by ion milling. it can. When using a limited-field diffraction image or a nanobeam diffraction image, a diffraction pattern is formed when the diffraction pattern is amorphous, whereas when it is not amorphous, diffraction spots caused by the crystal structure are formed. Is formed. When a bright field image or a high resolution image is used, the presence or absence of crystals can be confirmed by visual observation at a magnification of 1.00 × 10 ^{5 to} 3.00 × 10 ⁵ times. In this specification, when it can be confirmed that there is a crystal by ordinary X-ray diffraction measurement, it is assumed that “there is a crystal”, and it cannot be confirmed by ordinary X-ray diffraction measurement that there is a crystal, but by ion milling When it is possible to confirm that a crystal is present by obtaining a limited-field diffraction image, a nanobeam diffraction image, a bright-field image, or a high-resolution image using a transmission electron microscope on a thinned sample, Yes. "

  Here, by appropriately controlling the temperature of the roll 33 and the vapor pressure inside the chamber 35, the inventors can easily make the soft magnetic alloy ribbon before the heat treatment amorphous, and preferable nanocrystals after the heat treatment. It has been found that the part 11 and the amorphous part 13 can be easily obtained. Specifically, the temperature of the roll 33 is set to 50 to 70 ° C., preferably 70 ° C., and the vapor pressure inside the chamber 35 is adjusted to 11 hPa or less, preferably 4 hPa or less using Ar gas adjusted for dew point. It has been found that the soft magnetic alloy ribbon can be made amorphous easily.

  The temperature of the roll 33 is preferably 50 to 70 ° C., and the vapor pressure inside the chamber 35 is preferably 11 hPa or less. By controlling the temperature of the roll 33 and the vapor pressure inside the chamber 35 within the above range, the molten metal 32 can be cooled uniformly, and the resulting soft magnetic alloy can be easily made into a uniform amorphous ribbon before heat treatment. Become. There is no particular lower limit on the vapor pressure inside the chamber. The vapor pressure may be reduced to 1 hPa or less by filling with dew point-adjusted argon, or the vapor pressure may be reduced to 1 hPa or less in a state close to vacuum. Further, when the vapor pressure increases, it becomes difficult to make the ribbon before the heat treatment amorphous, and even if it becomes amorphous, it becomes difficult to obtain the above-mentioned preferable fine structure after the heat treatment described later.

  The preferable nanocrystal part 11 and amorphous part 13 can be obtained by heat-treating the obtained ribbon 34. At this time, if the ribbon 34 is completely amorphous, the above-described preferable fine structure can be easily obtained.

  In the present embodiment, the preferable fine structure is easily obtained by performing the heat treatment in two stages. The first stage heat treatment (hereinafter also referred to as first heat treatment) is performed for so-called distortion removal. This is to make the soft magnetic metal as uniform and amorphous as possible.

  In the present embodiment, the second stage heat treatment (hereinafter also referred to as second heat treatment) is performed at a higher temperature than the first stage. In order to suppress the self-heating of the ribbon in the second stage heat treatment, it is important to use a setter made of a material having high thermal conductivity. The setter material preferably has a low specific heat. Conventionally, alumina is often used as a material for the setter, but in the present embodiment, a material having higher thermal conductivity, such as carbon or SiC, can be used. Specifically, it is preferable to use a material having a thermal conductivity of 150 W / m or more. Furthermore, it is preferable to use a material having a specific heat of 750 J / kg or less. Furthermore, it is preferable to make the setter as thin as possible and place a control thermocouple under the setter to increase the thermal response of the heater.

  The advantages of performing the heat treatment in the above two steps will be described. The role of the first stage heat treatment will be described. The soft magnetic alloy forms an amorphous state by being rapidly cooled and solidified. At that time, since it is rapidly cooled from a high temperature, stress due to thermal shrinkage remains in the soft magnetic metal, and distortion and defects occur. In the first stage heat treatment, a uniform amorphous material is formed by relaxing strains and defects in the soft magnetic alloy by the heat treatment. Next, the role of the second stage heat treatment will be described. In the second heat treatment, αFe (-Si) crystals are generated. Strain and defects can be suppressed by the first stage heat treatment, and a uniform amorphous state is formed, so the particle diameter of the αFe (-Si) crystal generated by the second stage heat treatment is made uniform. can do. That is, αFe (-Si) crystals can be stably generated even when heat treatment is performed at a relatively low temperature. For this reason, the heat treatment temperature in the second heat treatment tends to be lower than the heat treatment temperature in the conventional one heat treatment. In other words, when the heat treatment is performed in one stage, the strain and defects remaining at the time of amorphous formation and the periphery thereof advance in advance to become an αFe (-Si) crystal, and the αFe (-Si) crystal The particle size cannot be made uniform. Furthermore, a heterogeneous phase composed of boride is formed, and the soft magnetic characteristics are deteriorated. In addition, in order to perform heat treatment as uniformly as possible by one-step heat treatment, it is necessary to form αFe (-Si) crystals as simultaneously as possible in the entire soft magnetic alloy. For this reason, the heat treatment temperature tends to be higher in the one-step heat treatment than in the two-step heat treatment described above.

  In the present embodiment, the preferred heat treatment temperature and the preferred heat treatment time for the first heat treatment and the second heat treatment vary depending on the composition of the soft magnetic alloy. In general, a composition containing Si tends to have a lower heat treatment temperature than a composition containing no Si. The heat treatment temperature of the first heat treatment is approximately 350 ° C. or more and 550 ° C. or less, and the heat treatment time is approximately 0.1 hours or more and 10 hours or less. The heat treatment temperature of the second heat treatment is approximately 475 ° C. or more and 675 ° C. or less, and the heat treatment time is approximately 0.1 hour or more and 10 hours or less. However, depending on the composition, there may be a preferred heat treatment temperature and heat treatment time outside the above range.

  When the heat treatment conditions are not suitably controlled, or when a suitable heat treatment apparatus is not selected, no subcomponent is contained in the nanocrystal part, oxidation resistance is reduced, and good soft magnetic properties are exhibited. It becomes difficult to obtain.

  Further, as a method for obtaining the soft magnetic alloy according to the present embodiment, there is a method for obtaining the soft magnetic alloy powder according to the present embodiment by, for example, a water atomizing method or a gas atomizing method other than the single roll method described above. Hereinafter, the gas atomization method will be described.

  In the gas atomization method, a molten alloy at 1200 to 1500 ° C. is obtained in the same manner as the single roll method described above. Thereafter, the molten alloy is sprayed in a chamber to produce a powder.

  At this time, by setting the gas injection temperature to 50 to 100 ° C. and the vapor pressure in the chamber to 4 hPa or less, it is finally easy to obtain the preferable microstructure described above.

  After the powder is produced by the gas atomization method, a suitable fine structure can be easily obtained by performing heat treatment in two stages as in the case of the single roll method. A soft magnetic alloy powder having particularly high oxidation resistance and good soft magnetic properties can be obtained.

  As mentioned above, although one Embodiment of this invention was described, this invention is not limited to said embodiment.

  There is no restriction | limiting in particular in the shape of the soft-magnetic alloy which concerns on this embodiment. As described above, a ribbon shape and a powder shape are exemplified, but a thin film shape, a block shape, and the like are also conceivable.

  There is no restriction | limiting in particular in the use of the soft-magnetic alloy which concerns on this embodiment. An example is a magnetic core. It can be suitably used as a magnetic core for an inductor, particularly a power inductor. The soft magnetic alloy according to the present embodiment can be suitably used for a thin film inductor, a magnetic head, and a transformer transformer in addition to a magnetic core.

  Hereinafter, a method for obtaining the magnetic core and the inductor from the soft magnetic alloy according to the present embodiment will be described. However, the method for obtaining the magnetic core and the inductor from the soft magnetic alloy according to the present embodiment is not limited to the following method.

  Examples of a method for obtaining a magnetic core from a ribbon-shaped soft magnetic alloy include a method of winding and laminating a ribbon-shaped soft magnetic alloy. When laminating thin ribbon-shaped soft magnetic alloys via an insulator, a magnetic core with further improved characteristics can be obtained.

  Examples of a method for obtaining a magnetic core from a powder-shaped soft magnetic alloy include a method in which a magnetic core is appropriately mixed with a binder and then molded using a mold. In addition, by applying an oxidation treatment, an insulating film or the like to the powder surface before mixing with the binder, the specific resistance is improved and the magnetic core is adapted to a higher frequency band.

  There is no restriction | limiting in particular in a shaping | molding method, Molding using a metal mold | die, mold shaping | molding, etc. are illustrated. There is no restriction | limiting in particular in the kind of binder, A silicone resin is illustrated. There is no particular limitation on the mixing ratio of the soft magnetic alloy powder and the binder. For example, a binder of 1 to 10% by mass is mixed with 100% by mass of the soft magnetic alloy powder.

For example, a space factor (powder filling rate) is 70% or more and 1.6% by mixing a binder of 1 to 5% by mass with 100% by mass of the soft magnetic alloy powder and compression molding using a mold. A magnetic core having a magnetic flux density of 0.4 T or more and a specific resistance of 1 Ω · cm or more when a magnetic field of × 10 ⁴ A / m is applied can be obtained. The above characteristics are superior to general ferrite cores.

Further, for example, by mixing 1 to 3% by weight of a binder with respect to 100% by weight of the soft magnetic alloy powder and compressing with a mold under a temperature condition equal to or higher than the softening point of the binder, the space factor is 80% As described above, a dust core having a magnetic flux density of 0.9 T or more and a specific resistance of 0.1 Ω · cm or more when a magnetic field of 1.6 × 10 ⁴ A / m is applied can be obtained. The above characteristics are superior to general dust cores.

  Furthermore, the core loss is further reduced and the usefulness is increased by heat-treating the formed body having the above-described magnetic core after the forming as a strain removing heat treatment.

  An inductance component can be obtained by winding the magnetic core. There are no particular restrictions on the manner in which the winding is applied and the method of manufacturing the inductance component. For example, a method of winding a winding at least one turn or more around the magnetic core manufactured by the above method can be mentioned.

  Further, when soft magnetic alloy particles are used, there is a method of manufacturing an inductance component by press-molding and integrating the winding coil in a state where the winding coil is built in the magnetic body. In this case, it is easy to obtain an inductance component corresponding to a high frequency and a large current.

  Further, when soft magnetic alloy particles are used, a soft magnetic alloy paste obtained by adding a binder and a solvent to the soft magnetic alloy particles and a paste obtained by adding a binder and a solvent to the conductor metal for the coil. An inductance component can be obtained by heating and firing after alternately laminating and laminating the conductive paste. Alternatively, by producing a soft magnetic alloy sheet using a soft magnetic alloy paste, printing a conductor paste on the surface of the soft magnetic alloy sheet, laminating and firing these, an inductance component in which the coil is built in the magnetic body is obtained. Can be obtained.

  Here, when producing an inductance component using soft magnetic alloy particles, it is excellent to use a soft magnetic alloy powder having a maximum particle size of 45 μm or less and a center particle size (D50) of 30 μm or less. It is preferable for obtaining the Q characteristic. In order to set the maximum particle size to 45 μm or less in terms of sieve diameter, a sieve having an opening of 45 μm may be used, and only the soft magnetic alloy powder passing through the sieve may be used.

  The Q value in the high frequency region tends to decrease as the soft magnetic alloy powder having a large maximum particle size is used. Particularly when the soft magnetic alloy powder having a maximum particle size exceeding 45 μm in the sieve diameter is used, The Q value may be greatly reduced. However, if the Q value in the high frequency region is not important, soft magnetic alloy powder having a large variation can be used. Since soft magnetic alloy powders with large variations can be manufactured at a relatively low cost, it is possible to reduce costs when using soft magnetic alloy powders with large variations.

  There is no restriction | limiting in particular in the use of the powder magnetic core which concerns on this embodiment. For example, it can be suitably used as a magnetic core for an inductor, particularly a power inductor.

  Hereinafter, the present invention will be specifically described based on examples.

(Experiment 1)
Various raw materials were weighed so as to obtain a master alloy having a composition of Fe: 84 atomic%, B: 9.0 atomic%, and Nb: 7.0 atomic%. And after evacuating in a chamber, it melt | dissolved by the high frequency heating and produced mother alloy.

  Thereafter, the prepared master alloy is heated and melted to obtain a metal in a molten state of 1300 ° C., and then the metal is jetted onto the roll by a single roll method with a roll temperature of 70 ° C. and a vapor pressure of 4 hPa in the chamber. It was created. Moreover, the thickness of the ribbon obtained by appropriately adjusting the rotation speed of the roll was set to 20 μm. The vapor pressure was adjusted by using Ar gas with dew point adjustment.

  Next, heat treatment was performed on each of the produced ribbons to obtain a single plate-like sample. In this experimental example, sample no. Samples other than 7-12 were heat-treated twice. Table 1 shows the heat treatment conditions. Moreover, when heat-treating each ribbon, the ribbon was placed on a setter made of the material shown in Table 1, and a control thermocouple was placed under the setter. The setter thickness at this time was unified at 1 mm. Alumina having a thermal conductivity of 31 W / m and a specific heat of 779 J / kg was used. Carbon having a thermal conductivity of 150 W / m and a specific heat of 691 J / kg was used. SiC (silicon carbide) having a thermal conductivity of 180 W / m and a specific heat of 740 J / kg was used.

  After pulverizing and pulverizing a part of each ribbon before heat treatment, X-ray diffraction measurement was performed to confirm the presence or absence of crystals. Furthermore, the presence or absence of microcrystals was confirmed by observing a limited-field diffraction image and a bright-field image at 300,000 times using a transmission electron microscope. As a result, it was confirmed that the ribbons of the examples and comparative examples were amorphous with no crystals and microcrystals present. In addition, it was confirmed by ICP measurement and fluorescent X-ray measurement that the composition of the whole sample almost coincided with the composition of the mother alloy.

  And the saturation magnetic flux density and coercive force of each sample after heat-treating each ribbon was measured. The results are shown in Table 1. The saturation magnetic flux density (Bs) was measured at a magnetic field of 1000 kA / m using a vibrating sample magnetometer (VSM). The coercive force (Hc) was measured at a magnetic field of 5 kA / m using a direct current BH tracer. Each sample was evaluated for oxidation resistance. Specifically, a high-temperature moisture resistance test was performed for 3 hours at a temperature of 80 ° C. and a humidity of 85%, and the surface was observed to determine whether spot rust was formed. The results are shown in Table 1.

  Furthermore, the observation range of 40 nm × 40 nm × 200 nm was observed for each sample using 3DAP (three-dimensional atom probe), and it was confirmed that all the samples included a nanocrystal part and an amorphous part. Furthermore, the nanocrystal part composition and the amorphous part composition were measured using 3DAP. The results are shown in Table 2. Furthermore, the average particle diameter of the nanocrystals in the nanocrystal part and the crystallinity in the nanocrystal part were also calculated using XRD. The results are shown in Table 2.

  From Table 1, the material of the setter is carbon or SiC having relatively high thermal conductivity and relatively low specific heat, and the heat treatment temperature is performed in two stages, and the first heat treatment temperature and the second heat treatment temperature are appropriately controlled. In the examples, oxidation resistance was particularly good. On the other hand, the material of the setter is Sample No. 2 in which the heat conductivity is relatively low and the specific heat is relatively high. 1-5, sample No. 1 subjected to heat treatment in one stage 7-12, sample No. 2 in which the temperature of the second heat treatment was too high. 19 and 39, sample No. 1 in which the temperature of the first heat treatment was too low. 20 and Sample No. in which the temperature of the first heat treatment was too high. All of 24a resulted in inferior oxidation resistance to the examples.

  According to Table 2, each example contained M1 (Nb) and / or M2 (B) in the nanocrystal part, whereas each comparative example did not contain M1 and M2 in the nanocrystal part. I understand.

(Experiment 2)
Various master alloys having compositions of Fe: 73.5 atomic%, Cu: 1.0 atomic%, Nb: 3.0 atomic%, Si: 13.5 atomic%, and B: 9.0 atomic% are obtained. Raw material metals and the like were weighed. And after evacuating in a chamber, it melt | dissolved by the high frequency heating and produced mother alloy. Hereinafter, in the same manner as in Experiment 1, sample No. 40-63 samples were prepared. The results are shown in Table 3 and Table 4.

  In addition, the X-ray-diffraction measurement was performed with respect to each thin strip before heat processing, and the presence or absence of the crystal | crystallization was confirmed. Furthermore, the presence or absence of microcrystals was confirmed by observing a limited-field diffraction image and a bright-field image at 300,000 times using a transmission electron microscope. As a result, it was confirmed that the ribbons of the examples and comparative examples were amorphous with no crystals and microcrystals present. It was confirmed by ICP measurement and fluorescent X-ray measurement that the composition of the entire sample almost coincided with the composition of the mother alloy.

  From Table 3, the material of the setter is carbon or SiC with relatively high thermal conductivity and relatively low specific heat, and the heat treatment temperature is performed in two stages, and the first heat treatment temperature and the second heat treatment temperature are appropriately controlled. In the examples, oxidation resistance was particularly good. On the other hand, the material of the setter is Sample No. 2 in which the heat conductivity is relatively low and the specific heat is relatively high. 40-45, sample No. 1 subjected to heat treatment in one stage. 46-51, sample No. 2 in which the temperature of the second heat treatment was too high. Nos. 56, 57, 62 and 63 were inferior to the examples because both the soft magnetic properties and the oxidation resistance were not compatible.

  From Table 4, each example contained M1 (Nb), M2 (B) and / or Cu in the nanocrystal part, whereas each comparative example contained M1, M2 and Cu in the nanocrystal part. You can see that it was not.

(Experimental example 3)
In Experimental Example 3, the composition of the mother alloy was changed to the compositions shown in Tables 5 to 9. And it carried out on the same conditions as Experimental example 1 and Experimental example 2 until the heat treatment process. And the difference in coercive force and oxidation resistance was confirmed between the case where the heat treatment was carried out in one stage and the case where it was carried out in two stages. The results are shown in Tables 5-9. When heat treatment was performed in one stage, the temperature was set at 675 ° C. for 60 minutes. When heat treatment was performed in two stages, the first heat treatment was performed at 450 ° C. for 60 minutes, and the second heat treatment was performed at 650 ° C. for 60 minutes. The heat treatment was carried out using the same carbon as in Experimental Example 1 as the setter material. In the case where crystals were present in the ribbon before the heat treatment, the coercive force in the one-step heat treatment was remarkably increased, so that the two-step heat treatment was not performed. For the sample after the two-step heat treatment, the content (α) of M1 + M2 + Cu in the nanocrystal part and the content (β) of M1 + M2 + Cu in the amorphous part were measured using 3DAP. Furthermore, the average particle diameter of the nanocrystal and the crystallinity of the nanocrystal part were also measured. As for oxidation resistance, a high temperature humidity resistance test was performed at a temperature of 80 degrees and a humidity of 85%, and the surface was observed every 30 minutes to determine whether spot rust was formed. When the time until spot rust generation in the two-stage heat treatment is 2.0 times or more than the time until spot rust occurrence in the one-stage heat treatment ◎, when the time is 1.2 times or more and less than 2.0 times, The case of more than 1.0 times and less than 1.2 times was indicated by Δ, and the case of 1.0 times or less was indicated by ×. In addition, it is excellent in the order of ◎, ○, Δ, and ×, and in this experimental example, a case where the evaluation is Δ or more is considered good.

  In each example, even when the composition was changed as appropriate, in the case where the heat treatment was performed in two stages, the coercive force was remarkably reduced and the oxidation resistance was improved as compared with the case where the heat treatment was performed in one stage. In addition, when heat treatment was performed in two stages, M1, M2 and / or Cu existed in the nanocrystal part.

(Experimental example 4)
In Experimental Example 4, the composition of the master alloy was changed to the composition shown in Table 10. And it carried out on the same conditions as Experimental example 1 and Experimental example 2 until the heat treatment process. And the difference in coercive force and oxidation resistance was confirmed between the case where the heat treatment was carried out in one stage and the case where it was carried out in two stages. The results are shown in Table 10. When heat treatment was performed in one stage, the heat treatment was performed at 450 ° C. for 60 minutes. When heat treatment was performed in two stages, the first heat treatment was performed at 350 ° C. for 60 minutes, and the second heat treatment was performed at 425 ° C. for 60 minutes. The heat treatment was carried out using the same carbon as in Experimental Example 1 as the setter material. In the case where crystals were present in the ribbon before the heat treatment, the coercive force in the one-step heat treatment was remarkably increased, so that the two-step heat treatment was not performed. For the sample after the two-step heat treatment, the content (α) of M1 + M2 + Cu in the nanocrystal part and the content (β) of M1 + M2 + Cu in the amorphous part were measured using 3DAP. Furthermore, the average particle diameter of the nanocrystal and the crystallinity of the nanocrystal part were also measured. As for oxidation resistance, a high temperature humidity resistance test was performed at a temperature of 80 degrees and a humidity of 85%, and the surface was observed every 30 minutes to determine whether spot rust was formed. When the time until spot rust generation in the two-stage heat treatment is 2.0 times or more than the time until spot rust occurrence in the one-stage heat treatment ◎, when the time is 1.2 times or more and less than 2.0 times, The case of more than 1.0 times and less than 1.2 times was indicated by Δ, and the case of 1.0 times or less was indicated by ×. In addition, it is excellent in the order of ◎, ○, Δ, and ×, and in this experimental example, a case where the evaluation is Δ or more is considered good.

  In each Example of Experimental Example 4, even when the composition was appropriately changed, the coercive force was significantly reduced and the oxidation resistance was improved in the case where the heat treatment was performed in two stages as compared with the case where the heat treatment was performed in one stage. In addition, when heat treatment was performed in two stages, M1, M2 and / or Cu existed in the nanocrystal part.

(Experimental example 5)
In Experimental Example 5, the composition of the mother alloy was changed to the composition shown in Table 11. And it carried out on the same conditions as Experimental example 1 and Experimental example 2 until the heat treatment process. And the difference in coercive force and oxidation resistance was confirmed between the case where the heat treatment was carried out in one stage and the case where it was carried out in two stages. The results are shown in Table 11. When heat treatment was performed in one stage, the heat treatment was performed at 550 ° C. for 60 minutes. When heat treatment was performed in two stages, the first heat treatment was performed at 425 ° C. for 60 minutes, and the second heat treatment was performed at 525 ° C. for 60 minutes. The heat treatment was carried out using the same carbon as in Experimental Example 1 as the setter material. In the case where crystals were present in the ribbon before the heat treatment, the coercive force in the one-step heat treatment was remarkably increased, so that the two-step heat treatment was not performed. For the sample after the two-step heat treatment, the content (α) of M1 + M2 + Cu in the nanocrystal part and the content (β) of M1 + M2 + Cu in the amorphous part were measured using 3DAP. Furthermore, the average particle diameter of the nanocrystal and the crystallinity of the nanocrystal part were also measured. As for oxidation resistance, a high temperature humidity resistance test was performed at a temperature of 80 degrees and a humidity of 85%, and the surface was observed every 30 minutes to determine whether spot rust was formed. When the time until spot rust generation in the two-stage heat treatment is 2.0 times or more than the time until spot rust occurrence in the one-stage heat treatment ◎, when the time is 1.2 times or more and less than 2.0 times, The case of more than 1.0 times and less than 1.2 times was indicated by Δ, and the case of 1.0 times or less was indicated by ×. In addition, it is excellent in the order of ◎, ○, Δ, and ×, and in this experimental example, a case where the evaluation is Δ or more is considered good.

  In each Example of Experimental Example 5, even when the composition was appropriately changed, the coercive force was significantly reduced and the oxidation resistance was improved in the case where the heat treatment was performed in two stages as compared with the case where the heat treatment was performed in one stage. In addition, when heat treatment was performed in two stages, M1, M2 and / or Cu existed in the nanocrystal part.

(Experimental example 6)
In Experimental Example 6, the evaluation was performed under the same conditions as in Experimental Example 3 except that the composition of the mother alloy was changed to the composition shown in Table 12. The results are shown in Table 12.

  In each example, even when the composition was changed as appropriate, in the case where the heat treatment was performed in two stages, the coercive force was remarkably reduced and the oxidation resistance was improved as compared with the case where the heat treatment was performed in one stage. In addition, when heat treatment was performed in two stages, M1, M2 and / or Cu existed in the nanocrystal part.

(Experimental example 7)
In Experimental Example 7, various raw materials were weighed so that a mother alloy having the composition shown in Table 13 was obtained. And after evacuating in a chamber, it melt | dissolved by the high frequency heating and produced mother alloy.

    Thereafter, the produced master alloy was heated and melted to obtain a metal in a molten state at 1500 ° C., and then the metal was sprayed under the composition conditions shown in Table 13 below by a gas atomizing method to prepare a powder. In Experiment 7, a sample was prepared with a gas injection temperature of 100 ° C. and a vapor pressure in the chamber of 4 hPa. The vapor pressure was adjusted by using Ar gas with dew point adjustment.

    Each powder was subjected to one-step heat treatment or two-step heat treatment under the conditions shown in Table 13 to evaluate magnetic properties and oxidation resistance. Furthermore, the observation range of 40 nm × 40 nm × 200 nm was observed for each sample powder using 3DAP (three-dimensional atom probe), and it was confirmed that all the sample powders contained nanocrystal parts and amorphous parts. The material of the setter during the heat treatment was carbon. Furthermore, the nanocrystal part composition and the amorphous part composition were measured using 3DAP. The results are shown in Table 13. Furthermore, the average particle diameter of the nanocrystals in the nanocrystal part and the crystallinity in the nanocrystal part were also calculated using 3DAP. The results are shown in Table 14. As for oxidation resistance, a high-temperature moisture resistance test was conducted for 1 hour at a temperature of 80 degrees and a humidity of 85%, and the surface was observed to determine whether or not rust was formed.

  In each Example in which the heat treatment was performed in two stages, M1, M2 and / or Cu were contained in the nanocrystal part, and the oxidation resistance was improved. On the other hand, each comparative example in which the heat treatment was performed in one stage did not contain M1, M2 and Cu in the nanocrystal part, and the oxidation resistance was lowered.

DESCRIPTION OF SYMBOLS 11 ... Nanocrystal part 13 ... Amorphous part 31 ... Nozzle 32 ... Molten metal 33 ... Roll 34 ... Strip 35 ... Chamber

Claims (9)

A soft magnetic alloy comprising a nanocrystalline part and an amorphous part,
The nanocrystal part contains αFe (-Si) as a main component, and B, P, C, Ti, Zr, Hf, Nb, Ta, Mo, V, W, Cr, Al, Mn, Zn, Cu as subcomponents. see contains one or more elements selected from the total content of subcomponents in the nanocrystals unit alpha (at%), the total content of subcomponents of the nanocrystals unit included in the amorphous portion Is β (at%), 0.01 ≦ (α / β) ≦ 0.40, and the crystallinity is 5% or more and 70% or less,
The soft magnetic alloy is a soft magnetic alloy represented by a composition formula Fe _a Cu _b M1 _c Si _d M2 _e ,
M1 is at least one selected from Ti, Zr, Hf, Nb, Ta, Mo, V, W, Cr, Al, Mn, Zn,
M2 is at least one selected from B, P, and C,
a + b + c + d + e = 100
64.9 ≦ a ≦ 94.5
0.0 ≦ b ≦ 3.0
0.0 ≦ c ≦ 15.5
0.0 ≦ d ≦ 17.5
2.0 ≦ e ≦ 23.0
And
A soft magnetic alloy , wherein at least one of c and d is not 0 .   The soft magnetic alloy according to claim 1, wherein the degree of crystallinity is 15% or more and 70% or less.   3. The soft magnetic alloy according to claim 1, wherein a total content ratio of subcomponents in the nanocrystal portion is α ≦ at ≦ 20, and 0.5 ≦ α ≦ 20.   The soft magnetic alloy according to any one of claims 1 to 3, wherein 10≤β≤60, where β (at%) is a total content of subcomponents of the nanocrystal part contained in the amorphous part.   Assuming that the total content of subcomponents in the nanocrystal part is α (at%) and the total content of subcomponents of the nanocrystal part contained in the amorphous part is β (at%), 0.05 <( The soft magnetic alloy according to claim 1, wherein α / β) <0.20. The soft magnetic alloy according to claim 1, wherein 0.0 ≦ c ≦ 15.0 and 2.0 ≦ e ≦ 20.0 .   The soft magnetic alloy according to any one of claims 1 to 6, which has a ribbon shape.   It is a powder form, The soft-magnetic alloy in any one of Claims 1-6.   A magnetic component comprising the soft magnetic alloy according to claim 1.

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